Chap. XVIII. CHANGED CONDITIONS. 141 



to Gulls, though many have been kept in the Zoological Gardens 

 and in the old Surrey Gardens, no instance was known before the 

 year 1818 of their coupling or breeding; but since that period the 

 herring gull (Larus argerrfatus) has bred many times in the 

 Zoological Gardens and at Knowsley. 



There is reason to believe that insects are affected by confinement 

 like the higher animals. It is well known that the Sphingidse 

 rarely breed when thus treated. An entomologist 60 in Paris kept 

 twenty-five specimens of Saturnia pyri, but did not succeed in 

 getting a single fertile egg. A number of females of Orthosia munda 

 and of Mamestra suasa reared in confinement were unattractive to 

 the males. 61 Mr. Newport kept nearly a hundred individuals of 

 two species of Vanessa, but not one paired ; this, however, might 

 have been due to their habit of coupling on the wing. 62 Mr. 

 Atkinson could never succeed in India in makiDg the Tarroo silk- 

 moth breed in confinement. 63 It appears that a number of moths, 

 especially the Sphingidse, when hatched in the autumn out of their 

 proper season, are completely barren; but this latter case is still 

 iuvolved in some obscurity. 64 



Independently of the fact of many animals under confine- 

 ment not coupling, or, if they couple, not producing young, 

 there is evidence of another kind that their sexual functions 

 are disturbed. For many cases have been recorded of the 

 loss by male birds when confined of their characteristic plu- 

 mage. Thus the common linnet (Linota cannabina) when 

 caged does not acquire the fine crimson colour on its breast, 

 and one of the buntings (Emberiza passerina) loses the black 

 on its head. A Pyrrhula and an Oriolus have been observed 

 to assume the quiet plumage of the hen-bird ; and the Fcdco 

 albidus returned to the dress of an earlier age. 65 Mr. Thomp- 

 son, the superintendent of the Knowsley menagerie, informed 

 me that he had often observed analogous facts. The horns 

 of a male deer (Cervus canadensis) during the voyage from 

 America were badly developed ; but subsequently in Faris 

 perfect horns were produced. 



60 Loudon's ' Mag. of Nat. Hist.,' 5764 ; and Dr. Wallace, in ' Proc. 

 vol. v., 1832, p. 153. Entomolog. Soc.,' June 4th, 1860, p. 



61 ' Zoologist,' vols, v.-vi., 1847-48, 119. 



p. 1660. 65 Yarrell's 'British Birds,' vol. i. 



62 ' Tonsact. Entomolog. Soc.,' vol. p. 506 ; Bechstein, ' Stubenvogel,' s. 

 iv., 1845, p, 30. 185 ; ' Phiiosoph. Transact.,' 1772, p. 



63 'Transact. Linn. Soc.,' vol. vii. 271. Bronn (' Geschichte der Natur,' 

 p. 40. Band ii. s. 96) has collected a number 



64 See an interesting paper by Mr. of cases. For the case of the deer, see 

 Newman, in the 'Zoologibt,' 1857, p. ' Penny Cyclop.,' vol. viii. p. 350. 



